Serapha Bio

About Serapha Bio

Serapha Bio is a clinical-stage biotechnology company focused on developing a novel gene therapy for Alpha-1 Antitrypsin Deficiency (AATD). The company was co-founded in 2026 by life sciences investment firms RTW Investments, LP, and RA Capital Management to advance a specific clinical asset. In June 2026, Serapha Bio entered into a definitive agreement for a reverse merger with Boundless Bio (Nasdaq: BOLD). Upon completion, expected in the fourth quarter of 2026, the combined entity will operate as Serapha Bio and trade on the Nasdaq under the ticker symbol AATD. This transaction provides Serapha with a public market platform and significant capital. Concurrent with the merger, the company secured approximately $230 million in private investment commitments from a syndicate of healthcare investors co-led by its founding firms. This financing, which includes a $138 million Series A round, is expected to fund operations into the second half of 2029. The company's lead product candidate is SERP-01, an investigational in vivo base editing therapy designed to correct the SERPINA1 E342K (PiZ) mutation, which is the primary genetic cause of severe AATD. By correcting this mutation at its source, the therapy aims to restore the production of functional Alpha-1 Antitrypsin protein to normal physiologic levels. Serapha Bio licensed SERP-01 (formerly YOLT-202) from YolTech Therapeutics in June 2026, acquiring rights outside of the Greater China region. YolTech is eligible for future milestone payments and royalties and continues to study the therapy in an Investigator-Initiated Trial in China, which has produced encouraging early clinical data.